You can't. Unless your application is dependent on the correct setting of current time in another way, e.g. in what's printed by the reports it produces. It's not a major concern, don't worry about it. Consider the cost of finding an enforcement technique against the loss of sales caused by clock resets, and the loss of goodwill caused by the enforcement technique ... It's really not worth worrying about. The inconvenience of setting the clock wrong is generally just too great.